C code for modified Euler

#include<stdio.h>

float equation(float x,float y)

{

    float z;

    z=(x*x*x)+y;

    return z;

}

void main()

{

    float f,x,y[20],h,n,Y1,Y2,yn;

    int i,m;

    printf("Enter initial value of x:");

    scanf("%f",&x);

    printf("Enter initial value of y:");

    scanf("%f",&y[0]);

    printf("Enter Interval Size:");

    scanf("%f",&h);

    printf("Enter value to be found:");

    scanf("%f",&n);

    m=n/h;

    printf("x        y\n");

    //printf("%f    %f\n",x,y[0]);

   

    for(i=1;i<=m;i++)

    {   

        printf("%f    %f\n",x,y[i-1]);

        yn=y[i-1]+(h*equation(x,y[i-1]));

        do

        {       

        Y1=y[i-1]+(h*(equation(x,y[i-1])+equation(x+h,yn)))/2;

        Y2=y[i-1]+(h*(equation(x,y[i-1])+equation(x+h,Y1)))/2;

        yn=Y2;

        }while((Y1-Y2)<0.01 || (Y2-Y1)<0.01);

        y[i]=Y2;       

        x=x+h;

    }   

    printf("\ny(%f)=%f\n",n,y[m-1]);

}